This invention relates to marine seismic cables, and, more particularly, to a towed seismic cable which flexible solid materials, disposed within the cable, buoyantly support.
For many years, the marine seismic exploration industry has relied on fluid-filled seismic cables. Marine seismic cables are one of the most critical components aboard today's seismic exploration vessels, and have a direct affect on the accuracy of the results which researchers and technicians obtain. The amount and type of fluid in oil-filled cables must be adjusted dependent on changes in water temperature and/or salinity. Also, oil-filled cables are prone to leakage. The outer jacket of the seismic cables of the prior art is prone to rupture or tearing. This is particularly undesirable because this exposes the internal electrical components to seawater, and disrupts the buoyancy of the cable.
Some of the hazards which seismic cables face include underwater obstructions, fishing vessels, and sea animals. These hazards can sever cables, which may then sink, and, consequently, cause significant downtime and lost efficiencies.
U.S. Pat. Nos. 5,089,668, 5,141,796, and 5,471,436 disclose the use of a buoyant material to permit solid or semi-solid composition of a seismic cable. However, in these cases, the positioning or housing of hydrophones is not discussed.
The industry needs a seismic cable which is streamlined, buoyant even when the jacket ruptures, durable, and which requires little maintenance. The industry needs a seismic cable which requires less change-over time to accommodate different marine environments. The industry needs a seismic cable which minimizes hydrophone noise generated by the relative motion of cable components.